There’s not going to be a lot of ho-ho-ho at Walmart this holiday season.

The country’s No. 1 retailer yesterday issued a disappointing forecast for the holiday quarter and said a bribery probe that has ensnared the discounter in Mexico has widened to Brazil, China and India.

At the same time, disgruntled workers said they will stage strikes and protests at 1,000 stores nationwide in the days leading up to the crucial post-Thanksgiving weekend. The triple whammy sent shares of the Bentonville, Ark., retailer down 3.6 percent.

Hounded by persistently high unemployment, the lower-income customers of the retail giant have been buying fewer name-brand household products and groceries, and trading down to chicken from beef to save pennies, execs said.

Sales at stores open at least a year, or same-store sales, a closely watched retail metric, rose just 1.5 percent in the three months ended Oct. 31, slowing from growth of more than 2 percent in the first half and missing analysts’ forecasts.

Walmart shares fell to $68.72 on the news, their biggest one-day drop in more than six months.

In response to the lean times, Walmart has been cutting prices and has announced an aggressive plan to open stores at 8 p.m. on Thanksgiving to dangle doorbuster deals on toys, electronics and clothing.

In an unprecedented move, Walmart said it will guarantee deals on TVs, Blu-ray players and Apple’s iPad 2 for all customers lining up outside its stores on Thanksgiving evening.

“There’s no way they’re not going to draw a large amount of share doing that,” says Brad Wilson, president of Brad’s Deals, an online coupon site.

But Walmart’s Thanksgiving sales events are also riling some employees, who complain that turkey dinners cut short will be the latest example of unpalatable work schedules, with shifts that increasingly are unpredictable and skimpy on hours.

Desperate to trim costs, Walmart isn’t staffing stores with enough workers to help customers — a key reason for sluggish sales, said John Marshall, an analyst at the United Food and Commercial Workers.

A worker group called OUR Walmart said yesterday that employee protests and strikes began on the West Coast this week, and will spread to cities including Chicago, Dallas and Miami in the days leading up to Thanksgiving.

Separately, Walmart said it was looking into potential violations related to the Foreign Corrupt Practices Act in Brazil, China and India. The company continues to work with government officials in the US and Mexico on that probe.